The violent resolution of intergroup conflict has plagued the world for all of known history. The major focus of this proposed research is identifying ways to increase cooperativeness in intergroup interactions. By contrasting the consequences that occur when someone is behaving as part of a group, compared to behaving as an individual, our previous research established a clear discontinuity. That is, using a mixed-motive paradigm and face-to-face interaction, repeated group or group interactions typically produce high rates of competition, while interactions of two people from these groups are typically characterized by high rates of cooperation. Such discontinuity occurs even though competition yields worse results than does mutual cooperation. Existing evidence indicates that such discontinuity is a very robust phenomenon. It is explained partially by the greater tendency of groups than individuals to distrust, or fear, each either and partially by the fact that group members can provide each other with social support for acting in a self- interested, or greedy manner, while individuals have no way of obtaining such social support. The proposed research has four foci. The first two involve attempts to reduce the magnitude of the discontinuity effect by: (1) providing evidence for the importance of a concern for future consequences and (2) increasing the salience of a common, ingroup identity. Third, in order to expand the ecological validity of our research program, we wish to initiate a series of studies investigating the consequences of mixed-motive interactions for disputants possessing unequal amounts of interpersonal power. Fourth, in order to better understand the conditions of applicability, the proposed research will also attempt to further validate the theoretical bases for the discontinuity effect. If the research is successful it will be possible to specify conditions under which discontinuity will occur and some of the methods by which it can be reduced.